/**
 * 题二
 */


const fp = require('lodash/fp')
const cars = [
  {
    name: 'Ferrari FF', horsepower: 660, dollar_value: 700000, in_stock: true
  },
  {
    name: 'Spyker C12 Zagato', horsepower: 650, dollar_value: 648000, in_stock: false
  },
  {
    name: 'Jaguar XKR-S', horsepower: 550, dollar_value: 132000, in_stock: false
  },
  {
    name: 'Audi R8', horsepower: 525, dollar_value: 114200, in_stock: false
  },
  {
    name: 'Aston Martin One-77', horsepower: 750, dollar_value: 1850000, in_stock: true
  },
  {
    name: 'Pagani Huayra', horsepower: 700, dollar_value: 1300000, in_stock: false
  }
]

// 练习1
let isLastInStock = fp.flowRight(fp.prop('in_stock'), fp.last)
console.log('ex1 test:')
console.log(isLastInStock(cars))
console.log('\n')

// 练习2
let firstName = fp.flowRight(fp.prop('name'), fp.first)
console.log('ex2 test:')
console.log(firstName(cars))
console.log('\n')

// 练习3
let _average = function (xs) {
  return fp.reduce(fp.add, 0, xs)/xs.length
}
let averageDollarValue = fp.flowRight(_average,fp.map(fp.prop('dollar_value')))
console.log('ex3 test:')
console.log(averageDollarValue(cars))
console.log('\n')

// 练习4
let _underscore = fp.replace(/\W+/g, '_')
let sanitizeNames = fp.map(fp.flowRight(_underscore, fp.toLower, fp.prop('name')))
console.log('ex4 test:')
console.log(sanitizeNames(cars))
console.log('\n')
